A Destructive Cascade Mediated by CCL2 Facilitates Prostate Cancer Growth in Bone

Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan MI 48109-1078, USA.
Cancer Research (Impact Factor: 9.33). 02/2009; 69(4):1685-92. DOI: 10.1158/0008-5472.CAN-08-2164
Source: PubMed


Monocyte chemoattractant protein 1 (CCL2) is a recently identified prominent regulator of prostate cancer growth and metastasis. The purpose of this study was to investigate the mechanistic role of CCL2 in prostate cancer growth in bone. The present study found that CCL2 was up-regulated in osteoblasts (3-fold by PC-3 and 2-fold by VCaP conditioned medium) and endothelial cells (2-fold by PC-3 and VCaP conditioned medium). Parathyroid hormone-related protein (PTHrP) treatment of osteoblastic cells up-regulated CCL2 and was blocked by a PTHrP antagonist, suggesting that prostate cancer-derived PTHrP plays an important role in elevation of osteoblast-derived CCL2. CCL2 indirectly increased blood vessel formation in endothelial cells through vascular endothelial growth factor-A, which was up-regulated 2-fold with administration of CCL2 in prostate cancer cells. In vivo, anti-CCL2 treatment suppressed tumor growth in bone. The decreased tumor burden was associated with decreased bone resorption (serum TRAP5b levels were decreased by 50-60% in anti-CCL2-treated animals from VCaP or PC-3 cell osseous lesions) and microvessel density was decreased by 70% in anti-CCL2-treated animals with bone lesions from VCaP cells. These data suggest that a destructive cascade is driven by tumor cell-derived, PTHrP-mediated induction of CCL2, which facilitates tumor growth via enhanced osteoclastic and endothelial cell activity in bone marrow. Taken together, CCL2 mediates the interaction between tumor-derived factors and host-derived chemokines acting in cooperation to promote skeletal metastasis.

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Available from: Linda A Snyder, Mar 02, 2015
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    • "These findings, along with CCL2 involvement in TAM-mediated actions, suggest that neutralizing CCL2 may provide a novel approach to controlling tumor growth. In preclinical studies in prostate cancer, anti-CCL2 antibodies suppressed tumor growth [17, 19] and formation of bone lesions [17] in murine models and attenuated cancer cell migration in in vitro human models [16]. A murine melanoma model showed reduced tumor size and angiogenesis when treated with a CCL2 inhibitor [20]. "
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    ABSTRACT: C-C chemokine ligand 2 (CCL2) stimulates tumor growth, metastasis, and angiogenesis. Carlumab, a human IgG1κ anti-CCL2 mAb, has shown antitumor activity in preclinical and clinical trials. We conducted a first-in-human phase 1b study of carlumab with one of four chemotherapy regimens (docetaxel, gemcitabine, paclitaxel + carboplatin, and pegylated liposomal doxorubicin HCl [PLD]). Patients had advanced solid tumors for which ≥1 of these regimens was considered standard of care or for whom no other treatment options existed. Dose-limiting toxicities included one grade 4 febrile neutropenia (docetaxel arm) and one grade 3 neutropenia (gemcitabine arm). Combination treatment with carlumab had no clinically relevant pharmacokinetic effect on docetaxel (n = 15), gemcitabine (n = 12), paclitaxel or carboplatin (n = 12), or PLD (n = 14). Total serum CCL2 concentrations increased post-treatment with carlumab alone, consistent with carlumab-CCL2 binding, and continued increase in the presence of all chemotherapy regimens. Free CCL2 declined immediately post-treatment with carlumab but increased with further chemotherapy administrations in all arms, suggesting that carlumab could sequester CCL2 for only a short time. Neither antibodies against carlumab nor consistent changes in circulating tumor cells (CTCs) or circulating endothelial cells (CECs) enumeration were observed. Three of 19 evaluable patients showed a 30 % decrease from baseline urinary cross-linked N-telopeptide of type I collagen (uNTx). One partial response and 18 (38 %) stable disease responses were observed. The most common drug-related grade ≥3 adverse events were docetaxel arm-neutropenia (6/15) and febrile neutropenia (4/15); gemcitabine arm-neutropenia (2/12); paclitaxel + carboplatin arm-neutropenia, thrombocytopenia (4/12 each), and anemia (2/12); and PLD arm-anemia (3/14) and stomatitis (2/14). Carlumab could be safely administered at 10 or 15 mg/kg in combination with standard-of-care chemotherapy and was well-tolerated, although no long-term suppression of serum CCL2 or significant tumor responses were observed.
    Full-text · Article · Jun 2014 · Targeted Oncology
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    • "Multiple studies demonstrate that PTHrP plays a major role in tumors that metastasize to the bone, such as breast and prostate cancer [13] [14] [15]. There is now increasing evidence that PTHrP also plays a role in cancers that metastasize to other regions of the body [16] [17] [18] [19] [20], such as colon tumors which show a preference for liver metastasis [2]. Apoptosis is especially relevant in the gastrointestinal tract, as this tissue undergoes a continued process of cell turnover that is essential for its normal function [21]. "
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    ABSTRACT: We have previously demonstrated that parathyroid hormone (PTH) induces apoptosis in human colon adenocarcinoma Caco-2 cells but the effects of its tumoral analog PTH-related peptide (PTHrP) in this cell line are still unknown. In the present work we investigated whether PTHrP, as PTH, is able to induce Caco-2 cells apoptosis or if it exerts protective effects under apoptotic conditions. Using Caco-2 cells cultured under serum deprivation in the presence or absence of PTHrP we demonstrated that, differently to PTH, its analog employed at the same concentration (10(-8)M) is not a pro-apoptotic hormone. Cells were exposed to an oxidative insult in the form of hydrogen peroxide to induce apoptosis, which leads to 50%-loss of cell viability determined by MTS assay, morphological changes observed under fluorescence microscopy and Western blot analysis. Herein we demonstrate, for the first time, that the pre-treatment with PTHrP prior to H2O2 incubation, prevents the cell death induced by the apoptotic inductor; and using specific inhibitors we evidenced that AKT, ERK1/2, JNK1/2 and p38 MAPK mediate this anti-apoptotic effect. Also, we found that PTHrP decreases the pro-apoptotic protein BAX levels and increases the protein expression of the anti-apoptotic HSP27. Immunoblot analysis revealed that H2O2 increases the phosphorylation levels of AKT and MAPKs, exhibiting a cellular defense response; and consequently increases phospho-BAD levels. The H2O2-induced activation of protein kinases is reverted when cells are pre-treated with PTHrP. Altogether these results evidence a protective effect of PTHrP under apoptotic conditions in intestinal cells, which may be mediated by AKT and MAPKs.
    Preview · Article · Jul 2013 · Biochimica et Biophysica Acta
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    • "Expression of CCL2 recruits tumor-associated macrophages, which is responsible for the prometastatic effect in the ER-negative breast cancers [6]. Moreover, CCL2 directly interacts with CCR2 on the endothelial cell surface, leading to increased vessel sprout formation and angiogenesis [7] [8]. It has been shown that polymorphisms of CCL2 and CCR2-64I are associated with transitional bladder cell carcinoma [9] [10]. "
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    ABSTRACT: The amount of monocyte chemoattractant protein-1 (MCP-1/CCL2) produced by a transitional cell carcinoma is directly correlated with high recurrence and poor prognosis in bladder cancer. However, the mechanisms underlying the effects of CCL2 on tumor progression remain unexplored. To investigate the role played by CCL2, we examined cell migration in various bladder cancer cell lines. We found that high-grade cancer cells expressing high levels of CCL2 showed more migration activity than low-grade bladder cancer cells expressing low levels of the chemokine. Although the activation of CCL2/CCR2 signals did not appreciably affect cell growth, it mediated cell migration and invasion via the activation of protein kinase C and phosphorylation of tyrosine in paxillin. Blocking CCL2 and CCR2 with small hairpin RNA (shCCL2) or a specific inhibitor reduced CCL2/CCR2-mediated cell migration. The antagonist of CCR2 promoted the survival of mice bearing MBT2 bladder cancer cells, and CCL2-depleted cells showed low tumorigenicity compared with shGFP cells. In addition to observing high-levels of CCL2 in high-grade human bladder cancer cells, we showed that the CCL2/CCR2 signaling pathway mediated migratory and invasive activity, whereas blocking the pathway decreased migration and invasion. In conclusion, high levels of CCL2 expressed in bladder cancer mediates tumor invasion and is involved with advanced tumorigenesis. Our findings suggest that this CCL2/CCR2 pathway is a potential candidate for the attenuation of bladder cancer metastases.
    Full-text · Article · May 2012 · Cytokine
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